2020-21 KTM 390 Adventure Bike Build
Above is a 2020 KTM 390 Adventure. After buying it and riding it stock, down the roads and out in the dirt and the bumps, I can honestly say it's a big dumb pig pig. Slow and heavy. Totally reminds me of buying the first Honda CRF 250 L, that came into Arizona, and developing it.
When I rode the 250L, outside of the dealership, I wanted to ask them to take it back and see if I could have my money back. Thing was, I bought it because a great price point at $5000 or whatever it was then. I also knew, that after I figured out the performance kit for it, that it would be totally different. And it worked. That bike weighed 300 lbs and had 18 hp stock. We got some weight off and got the power to 26 and it was a whole new bike. Honda sold a bunch of bikes and we sold a bunch of kits.
This new 390 KTM is the same kind of thing. It's on the heavy side, but some weight can come off. It feels odd and wrong, as far as ergonomics go. Especially for control in the dirt. But that can be fixed. And finally it needs more power, get up and go and some reliability. And we can definitely fix that.
As we started taking apart this bike, we realized how heavy the battery was. For about $100, you can loose a whole 6 lbs by going to a good lithium battery. This is high centered weight you feel. It's a must do
The people who design the best performance products ( us and just a few others ) know darn well to take measurements of stock componets first. On a fuel injected bike, the fuel pressure is so, so critical to performance and even maintaining stock running condition. The running pressure of the stock bike is 54 psi. If the pressure falls below this, then starting and acceleration will suffer. The lower it goes, the worse performance gets.
The next big parameter, that's super critical to know, on a fuel injected bike, is the air / fuel ratio. Now on this particular bike, it has an Oxygen sensor welded in the head pipe to make what we call a "closed loop" injection system. This means that the O2 sensor feeds back information to the ECU ( electronic control unit ). This means that the system tries to make adjustments to the fuel amount to the injector, so that the pre determined air/ fuel ratio is kept.
In the case of this bike, the pre determined air/ fuel ratio, seems to be 14.7 :1. That's what the gauge we hooked up to shows. When you ride down the street, the gauge fluctuates a bit, but it centers around 14.7.
When you crack the gas, there is a bit of an accelerator pump kick in, but not a lot. It shoots to 13.5 :1, which is a bit richer to aid in the "get up and go", but then goes right back to 14.7.
This is important to know. Because we need to know how far you can go with opening up exhaust and intake flow, before the ecu can't adjust anymore and the bike starts to lean out.